Small effects of a large sediment contamination with heavy metals on aquatic organisms in the vicinity of an abandoned lead and zinc mine

The effects of the long-term contamination of water reservoirs with mine effluents were investigated at an abandoned mine site in Upper Silesia, southern Poland. The studies covered metal content and mobility in bottom sediments as well as water chemistry in relation to the content of metals in selected macrophytes and their physiology and the composition of phyto- and zooplankton communities. Although it is 40 years since mining ceased, reservoir sediments are still heavily contaminated with cadmium, zinc and lead with concentrations (mg/kg), which vary roughly between 130–340, 10,000–50,000 and 4,000–12,000, respectively. About 50–80 % of these elements are associated with the reducible phase, and only a small percentage, <10 %, is present in the most mobile exchangeable phase. Despite the high total metal concentration in sediments, their content in the submerged plants Myriophyllum spicatum and the emerged plants Phragmites australis was low. The observed effects of heavy metal contamination on photosynthetic activity in the leaves of P. australis were negligible, whereas those in M. spicatum show up only as a difference in the distribution of photosynthetic activity in leaves of different ages, which seems to be related to the very good water quality and to the generally small concentrations of metals in pond water. The physicochemical properties of water also seem to control the presence of planktonic species more than does sediment contamination. However, a shift toward groups of species known to be more resistant to heavy metals (diatoms, green algae and Rotifera) indicates some adaptative changes related to the long-lasting contamination of ponds.     

Levels, distribution, and risk assessment of organochlorines in surficial sediments of the Red Sea coast, Egypt

The analyses of environmentally persistent pollutants like polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) isomers, and dichlorodiphenyltrichloroethane (DDT) and its metabolites in surficial sediment samples collected from 17 locations along with the coast of the Red Sea in Egypt were carried out using gas chromatography–mass spectrometry. Several potential organic contaminants from agricultural (e.g., DDT and its breakdown products, lindane, endrin, dieldrin, and endosulfan) and industrial (PCBs) sources were measured. The levels of 20 organochlorine pesticides (OCPs) and ten PCB congeners in sediment collected from 17 stations along ~1,200 km were investigated. Concentrations of PCBs, HCHs, DDTs, and cyclodienes ranged from 0.40 to 6.17, 0.01 to 0.09, n.d. to 0.46, and 0.08 to 0.90 ppb dry weight. Two statistical programs were applied on the data (principal component analysis, PCA, and cluster analysis, CA), and it was concluded that it is impossible to predict the distribution patterns of the OCPs in a contaminated area. Risk assessment of the organochlorines contaminated in the sediments of the studied area was investigated.     

Use of cellular automata in the study of variables involved in land use changes

The study of changes in land use has been included lately in territorial processes in order to optimize future management decisions. The different functions that the territory plays (production, aesthetic, and natural functions, etc.) make planning choices more difficult. This work focuses on the selection and combination of a set of indicators to analyze the variables through which the changes occur in the land used in viticulture for wine production. The proposed approach makes use of the Geographic Information System (GIS) in the development of a map of land use scenario. It is applied to a case study through a model involving cellular automata (CA) implemented with maps of suitability for viticulture and Markov chains. The use in this case of the CA is aimed at validating the scenario map in order to deduce the variables and the orientations of the farmers in the field of wine production.     

Distribution and ecological risk of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in surface sediments from the Bizerte lagoon,Tunisia

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in 18 surface sediment samples collected from Bizerte lagoon, Tunisia. The total concentrations of ten PCBs (∑PCBs) and of four OCPs (∑OCPs) in the sediments from this area ranged from 0.8 to 14.6 ng g^?1 dw (average value, 3.9 ng g^?1 dw) and from 1.1 to 14.0 ng g^?1 dw (average value, 3.3 ng g^?1 dw), respectively. Among the OCPs, the range of concentrations of dichlorodiphenyltrichloroethane and its metabolites (DDTs) and hexachlorobenzene (HCB) were 0.3–11.5 ng g^?1 dw (1.9 ng g^?1 dw) and 0.6–2.5 ng g^?1 dw (1.4 ng g^?1 dw), respectively. Compositional analyses of the POPs indicated that PCB 153, 138 and 180 were the predominant congeners accounting for 60 % of the total PCBs. In addition, p,p′-DDT was found to be the dominant DDTs, demonstrating recent inputs in the environment. Compared with some other regions of the world, the Bizerte lagoon exhibited low levels of PCBs and moderate levels of HCB and DDTs. The high ratios ΣPCBs/ΣDDTs indicated predominant industrial versus agricultural activities in this area. According to the established guidelines for sediment quality, the risk of adverse biological effects from such levels of OCPs and PCBs, as recorded at most of the study sites, was insignificant. However, the higher concentrations in stations S1 and S3 could cause biological damage.     

Foraminiferal biotopes and their distribution control in Ria de Aveiro (Portugal): a multiproxy approach

Ria de Aveiro, which is located in the centre of Portugal (40° 38′ N, 8° 45′ W), is a well-mixed and complex coastal lagoon that is separated from the sea by a sandy barrier and connects with the Atlantic through an artificial inlet. Tidal currents are the main factor controlling the lagoon’s hydrodynamics and, to a great extent, the sedimentary dynamic. The inner lagoonal zones receive input from several rivers and experience the pressure caused by the accumulation of organic matter and pollutants (namely, trace metals) from diverse anthropic activities. This paper is the first piece of work aiming to recognize, characterize and explain the main benthic foraminiferal biotopes in Ria de Aveiro. To provide a broad overview of this kind of setting, our results are compared to those of previous published studies conducted in similar transitional environments. The research is based on an investigation of 225 sites spread throughout this ecosystem. Utilizing a statistical approach, this study analyses the details of dead benthic foraminiferal assemblages composed of 260 taxa, the texture and composition (mineralogical and geochemical) of the sediment and physicochemical data. On the basis of the results of R-mode and Q-mode cluster analyses, several different biotopes can be defined as marsh biotope/near-marsh biotope; marginal urban/marginal urban mixing biotope; inner-outer lagoon biotope or enclosed lagoon; outer lagoon biotope, mixed sub-biotope; and outer lagoon, marine sub-biotope. These biotopes are related to foraminifera assemblages and substrate type and are influenced by local currents, water depth, chemical and physicochemical conditions, river or oceanic proximity, and anthropogenic impact, as evidenced by the mapping of the six factor loadings of the principal component analysis conducted herein. Based on a similar methodology of analysis as that applied in previous studies in the Lagoon of Venice, comparable biotypes were identified in Lagoon of Aveiro.     

Effects of sewage sludge amendments on pesticide sorption and leaching through undisturbed Mediterranean soils

The Gharb region in Morocco is an important agricultural zone where soils receive pesticide treatments and organic amendments to increase yields. The groundwater aquifer in the Gharb region is relatively shallow and thus vulnerable. The objective of this work was to study the influence of organic amendments on diuron, cyhalofop-butyl and procymidone leaching through undisturbed soil columns. Two soils were sampled from the Gharb region, a Dehs (sandy soil) and a R’mel (loamy clay soil). Following elution (124.5 mm), the amount of pesticide residues in the leachates of the sandy soil (0.06–0.21 %) was lower than in those of the loamy clay soil (0.20–0.36 %), which was probably due to preferential flow through the loamy clay soil. The amount of procymidone leached through the amended soil columns was greater than the control for the sandy soil only. The organic amendments did not significantly influence diuron and cyhalofop-butyl leaching in either of the soils. The application of organic amendments affected the amounts of dissolved organic matter (DOM) eluted and thus pesticide leaching as a function of soil-type. Nevertheless, in some case, the formation of pesticide-DOM complexes appeared to promote pesticide leaching, thus increasing groundwater contamination risks.     

Introduction

Abstract

Eight pairs of O‐methyl and O‐ethyl O‐(substituted‐phenyl) phenylphosphonothionates were evaluated with respect to their delayed neurotoxic activity in hens. O‐methyl compounds were in all cases more active than their O‐ethyl analogs. The neurotoxic potential of the O‐methyl phenylphosphonothionates was 2,5‐diCl >4‐NO₂ >2,4,5‐triCl and 2,4,6‐triCl >2,4‐diCl >2,5‐diCl‐4‐Br >4‐CN, when single oral doses were given. Both EPN‐ethyl and leptophos‐raethyl were more neurotoxic in multiple dermal than multiple oral dosing regimens. LD₅₀s for mice and flies were established.     

Biochemical effects of some organo‐phosphorus insecticides on new targets in white rats

Abstract

The three S‐n‐propyl phosphates and phosphothioates: RH 218, profenofos and prothiophos were compared with fenitrothion in their potential as inhibitors of rat liver and brain AChE. Fenitrothion was more potent as an inhibitor than the three S‐n‐propyl derivatives. Incubation of hepatic protein enhanced ChE inhibition in brain in the case of fenitrothion, while it reduced the inhibitory effect of the S‐n‐propyl derivatives. On the other hand, the four organophosphorus esters caused hypoglycemia in both male and female rats and also reduced their blood urea with different degrees.